Procedure for the semi-automatic detection of gastro-oesophageal reflux patterns in intraluminal impedance measurements in infants

The diagnosis of gastro-oesophageal reflux (GOR) is of great interest for p aediatric gastroenterologists. pH monitoring is the commonly used procedure for GOR diagnosis but a major amount of postprandial GOR is missed due to the mostly non-acidic gastric contents in infants. The multiple intralumina l impedance technique is based on the recording of the impedance changes du ring bolus transport inside the oesophagus. It is the first method which al lows the pH-independent, long-term registration of GOR. The use of the impe dance technology in clinical practice has been limited so far by the time-c onsuming, visual evaluation of the impedance traces. The new approach of a semi-automatic analysis of the impedance measurements allows the automated detection of reflux patterns. It is based on event ma rking and an optimised feature description of the impedance traces combined with a fuzzy system for pattern recognition. The classifier is developed a nd tested on 50 investigations in infants. Compared to the comprehensive, m ultiple visual evaluation the achieved precision is 75% sensitivity and 48% positive prediction. In comparison to a single visual evaluation the analy sis of the automatically proposed patterns corresponds to a 96% reduction o f the evaluation time with no loss of precision. Thus the applicability of the impedance technology is enhanced significantly. A combined measurement of pH and impedance gives evidence about the occurrence of GOR, its pH and the acidic exposure of the oesophagus. (C) 1999 IPEM. Published by Elsevier Science Ltd. All rights reserved.